The invention relates to an apparatus for carrying out chemical reaction sequences, having
a stack of reaction plates arranged one above another and optionally displaceably in relation to one another step by step in a direction of displacement perpendicular to the stacking direction, which plates are provided with passages arranged at the stepping interval, one of which in each case is formed as reaction chamber, PA1 a plate displacement device for the optional displacement of the respective plate in relation to the remaining plate stack by means of a plate displacement part drivable according to choice, which is movably mounted on a head of the plate displacement device which is movable according to choice in the stack direction between pate displacement positions allocated to the individual plates, and PA1 a tightening device having a presser part acting on the plate stack, which presser part is movable between a pressure application position with sealing clamping together of the plates and a release position with possibility of movement of the plates in relation to one another.
An apparatus of this kind is known (EP-A-164,206). With it it is possible simultaneously to carry out a series of biochemical reactions, especially the synthesis of DNA fragments, as also known per se from EP-A-181,491, using a stack of plates of circular disc form which can be rotated manually in relation to one another. The bases A, C, G, T are fed to the stack by way of four passages. According to the desired sequence the reaction chamber of the respective plate is brought into alignment with the passage delivering the desired base. The apparatus known from the initially mentioned EP-A-164,206 permits an automatic displacement (rotation) of the individual plates in relation to one another, so that a plurality, corresponding to the number of plates, of simultaneous synthesis reactions can be carried out with a high number of reaction steps in computer-supported manner without manual intervention. However in this known solution the apparatus expense is considerable. In all four drive systems are necessary: a height drive which drives a drive spindle for the height adjustment of the plate displacement device and a drive spindle for a shift lock a drive as part of the plate displacement device, which brings a plate displacement part in the form of a presser roller drivable according to choice by means of a further drive into and out of engagement with the external circumference of the respective plate; a fourth drive in the form of a lifting cylinder which serves for the movement of the presser part in the form of a plate. This plate is arranged above the plate stack and is movable between the release position, in which the plates are rotatable in relation to one another for the preparation of the next reaction, and the pressure application position, in which the plates are pressed together in sealing manner by the pressure application part. The reaction step in each case is carried out in the pressure application position.